1. Technical Field
The present invention relates to a structure for driving an electro-optical element.
2. Related Art
In the past, an electro-optical device using an electro-optical element such as an organic EL (Electroluminescence) element has been proposed. For example, a pixel circuit disclosed in JP-A-2006-30635 includes a storage capacitor which holds a voltage in accordance with an externally set gray scale, a driving transistor which generates a driving current in accordance with the voltage of the storage capacitor, and an electro-optical element which has a gray scale in accordance with a current amount of the driving current. The voltage across opposite ends of the storage capacitor is initialized by electrically connecting an initialization line to an electrode, where an initialization potential is supplied to the initialization line.
When the respective parts of the pixel circuit are arranged while overlapping with each other, a decrease in size (an increase in precision) of the pixel circuit is realized compared with a configuration in which the respective parts of the pixel circuit do not overlap with each other. From this viewpoint, for example, a configuration in which the initialization line is disposed while overlapping with a conductor (hereinafter, referred to as “gate conductor”) such as a wiring or an electrode electrically connected to a gate of the driving transistor may be supposed. However, since a capacitor is provided between the initialization line and the gate conductor facing each other, a variation in a potential of the gate conductor may occur with a variation in a potential of the initialization line when a current flows during the initialization of the storage capacitor. Since a current amount of the driving current is controlled in accordance with a potential of the gate of the driving transistor, a problem arises in that an error occurs in a gray scale of the electro-optical element due to a variation in a potential of the initialization line. On the other hand, in a configuration in which the initialization line does not overlap with the gate conductor, a problem arises in that an increase in precision of the pixel circuit is limited.